JP5867770B2 - Imaging device - Google Patents

Description

  The present invention relates to an image pickup apparatus that picks up an image of a subject formed by an image pickup optical system such as a lens using an image pickup element, and relates to an image pickup apparatus used in an environment where a temperature change is large.

  2. Description of the Related Art Image pickup apparatuses that pick up an image of a subject formed by an image pickup optical system such as a lens using an image pickup element have become widespread. In addition to being used for devices such as digital cameras and digital video cameras whose main functions are image pickup devices, image pickup devices (such as mobile phones, smartphones, PDAs, and notebook personal computers) are used in conjunction with downsizing of image pickup devices. Camera module) is additionally installed. Furthermore, the imaging apparatus can be used as a surveillance camera installed outdoors, or as an in-vehicle camera mounted on a moving body (for example, an automobile, a motorcycle, a bicycle, a ship, a flying body) for running recording or garage support. It is popular.

  Although the imaging device is used in various places as described above, the imaging device used in a severe environment where the temperature change is large, such as an in-vehicle camera, regardless of expansion or contraction of each part constituting the imaging device. It is required to exhibit stable performance. For example, when an imaging apparatus that does not have a focus adjustment function is assembled in a normal temperature environment (for example, an environment of about 20 ° C.) so that the focal point is aligned, the imaging apparatus is operated in a high temperature environment (for example, an environment of about 80 ° C.) When used, focus movement occurs due to expansion of the lens and the lens barrel (lens barrel) that holds the lens, and thus it is preferable to compensate for focus movement due to temperature changes.

  Patent Document 1 discloses a digital camera in which an expansion / contraction member that expands and contracts according to temperature is provided on the back surface of an image sensor. When a temperature change occurs, this digital camera compensates for the focus movement by automatically finely adjusting the position of the image sensor by the expansion and contraction of the expansion and contraction member.

  Patent Document 2 discloses an in-vehicle camera for infrared photographing in which a lens barrel has a double structure including an outer cylinder and an inner cylinder, and a focus movement due to a temperature change is suppressed. Specifically, the in-vehicle camera of Patent Document 2 has a structure in which a base end of an outer cylinder is fixed to a support body integrated with an image sensor, and a distal end of the outer cylinder is fixed to a distal end of the inner cylinder. By adjusting the material (thermal expansion coefficient) and length of the tube and the inner tube, the lens barrel expands toward the subject (expansion of the outer tube) relative to the support and the focal position due to the change in the refractive index of the lens Is offset by expansion from the tip of the outer cylinder to the image sensor side (expansion of the inner cylinder), so that the focal position is maintained on the image sensor even if there is a temperature change.

  In Patent Document 3, the lens barrel has a double structure of a lens holding part (inner cylinder) and an intermediate member (outer cylinder), and the lens holding part is attached to the intermediate member at three predetermined positions. An imaging device that is freely changeable is disclosed, and when focus movement occurs due to temperature change, it is disclosed that focus movement due to temperature change is suppressed by changing the mounting position of the lens holding unit. .

JP 2004-147188 A JP 2008-304641 A JP 2008-2111780 A

  Imaging devices used in environments with large temperature changes, such as in-vehicle cameras, must suppress focus movement due to temperature changes, as described above, but also prevent intrusion of foreign substances such as liquids such as water and dust. It may be required to prevent. Imaging devices used in harsh environments are often exposed not only to temperature changes but also to liquids and dust. When foreign objects such as liquids and dust enter the camera, the captured image may deteriorate due to condensation or dirt. This is because the control circuit may be short-circuited and damaged.

  For example, in the case of an in-vehicle camera, it goes without saying that it is installed outside a car, but even when it is installed inside a car, water or a cleaning liquid adheres to the inside of the imaging device when cleaning the room. May end up. In particular, when the lens barrel has a double structure to compensate for focus movement, the intrusion path for foreign matter such as liquid and dust is increased compared to a single lens barrel structure. It is required to prevent intrusion.

  In the imaging device described in Patent Document 1, a lens support portion that directly supports a lens is bonded to the inner surface of a cylindrical lens barrel base portion fixed to a drive substrate (CCD plate) of an imaging element. As a whole, it becomes a lens barrel with a double structure of the lens barrel base part and the lens support part, but the adhesive agent deteriorates due to repeated expansion and contraction of the lens barrel base part and the lens support part due to temperature change, In some cases, foreign substances such as liquid and dust are likely to enter.

  In the imaging apparatus described in Patent Document 2, the inner cylinder and the outer cylinder of the lens barrel are screwed together. When the expansion and contraction are repeated due to a temperature change, liquid or dust is discharged from these gaps. There is a possibility that foreign matter enters. Similarly, in the image pickup apparatus described in Patent Document 3, there is a possibility that foreign matters such as liquid and dust may enter from the gap between the intermediate member and the lens holding portion when the attachment position of the lens holding portion is changed.

  It is an object of the present invention to provide an imaging apparatus that suppresses focus movement due to temperature change and prevents entry of foreign matters such as liquid and dust.

  The imaging device of the present invention includes an imaging lens, an imaging element, and an intermediate member. The imaging lens is held by a lens barrel and forms an image of a subject. The imaging element captures an image of a subject formed by the imaging lens. The intermediate member is made of a material having a coefficient of linear expansion different from that of the lens barrel. The intermediate member has a flange portion that comes into contact with the lens barrel on the inner peripheral surface of one end. The surface of the lens barrel on the subject side and the flange portion of the intermediate member The lens barrel is held by joining the surfaces on the image sensor side.

  The surface of the lens barrel on the subject side and the contact surface of the flange portion of the intermediate member are between the surface of the imaging lens closest to the subject and the surface of the imaging element, and are closest to the subject side of the imaging lens. It is preferable to be provided closer to the subject than 1/3 of the distance between the surface and the surface closest to the image sensor.

  The subject side surface of the lens barrel and the flange portion of the intermediate member are preferably joined by an adhesive.

  At least one of the outer peripheral surface of the lens barrel or the inner peripheral surface of the intermediate member is provided with an adhesive reservoir adjacent to the subject side surface of the lens barrel and the contact surface of the flange portion of the intermediate member. Is preferred.

  The adhesive reservoir is preferably provided continuously, for example, on the entire outer circumference of the lens barrel or the inner circumference of the intermediate member. The adhesive reservoir may be provided at a part of the outer peripheral surface of the lens barrel or the inner peripheral surface of the intermediate member and at a plurality of locations.

It is preferable that the linear expansion coefficient of the lens barrel is in the range of 10 × 10 ⁻⁶ K ⁻¹ or more and 70 × 10 ⁻⁶ K ⁻¹ or less.

The linear expansion coefficient of the intermediate member is preferably within a range of 0.1 × 10 ⁻⁶ K ⁻¹ or more and 40 × 10 ⁻⁶ K ⁻¹ (1 / K) or less.
In addition, it is preferable that the subject-side surface of the lens barrel to be joined to the flange portion of the intermediate member is the front surface of the flange portion provided to protrude outward from the outer peripheral surface of the lens barrel.

  An imaging apparatus according to the present invention holds an imaging lens by a double structure in which a lens barrel and an intermediate member are joined, and the lens barrel and the intermediate member are provided with a flange portion and a lens barrel provided on an inner peripheral surface of the intermediate member. Therefore, the movement of the focus due to temperature change can be suppressed, and the entry of foreign matter such as liquid or dust can be prevented.

It is sectional drawing which shows schematic structure of an imaging device. It is sectional drawing which shows the point to which each part of an imaging device is joined. (A) And (B) is explanatory drawing which shows the thermal expansion of each part of an imaging device. It is sectional drawing which expands and displays the junction part of a lens barrel and an intermediate member. It is sectional drawing at the time of providing an adhesive reservoir in a flange part. It is a perspective view of the lens barrel which provided the adhesive reservoir in the perimeter of the flange part. It is a perspective view of the lens barrel which provided the adhesive agent pool in a part of flange part. It is sectional drawing at the time of providing the adhesive reservoir in the intermediate member. It is sectional drawing in the case of screwing an intermediate member and a lens holder.

  As shown in FIGS. 1 and 2, the imaging device 10 includes an imaging lens 11 and an imaging element 12, and an image of a subject formed by the imaging lens 11 is captured by the imaging element 12. The imaging device 10 is, for example, an in-vehicle camera installed in a car room.

  The imaging lens 11 is a fixed focus lens, and includes, for example, a lens, a mirror, a prism, and the like, and includes a member having substantially no power such as an optical filter as necessary. The optical axis L 1 of the imaging lens 11 is also the central axis of the lens barrel 13 and the intermediate member 15. In FIG. 1, an imaging lens 11 including six lenses is shown as an example, but the thickness and surface shape of each lens, the number of lenses, and the presence or absence of other members are arbitrary. The lenses constituting the imaging lens 11 are all glass lenses, for example, and are held by the lens barrel 13 while maintaining a predetermined positional relationship with each other.

  The lens barrel 13 has a cylindrical portion 13a and flange portions 13b and 13c, and is a substantially cylindrical member as a whole. The lens barrel 13 is bonded to the intermediate member 15, and the position with respect to the image sensor 12 is fixed via the intermediate member 15. That is, the imaging lens 11 is directly held by the lens barrel 13, but as a whole, the position with respect to the imaging element 12 is fixed by the double structure of the lens barrel 13 and the intermediate member 15.

  The cylindrical portion 13a is a cylindrical portion of the lens barrel 13, and holds each lens of the imaging lens 11 by bonding or the like. For this reason, protrusions (not shown) for positioning each lens of the imaging lens 11 are appropriately provided on the inner surface side of the cylindrical portion 13a.

  The flange portions 13b and 13c are provided on the side surface of the cylindrical portion 13a so as to protrude outward (in a direction away from the optical axis L1). Moreover, the flange parts 13b and 13c are provided in the perimeter of the cylindrical part 13a. What is on the subject side (left side in FIG. 1) is the flange portion 13b, and what is on the imaging element 12 side (right side in FIG. 1) is the flange portion 13c. Moreover, the cross section of the flange parts 13b and 13c by the surface containing the optical axis L1 is substantially square. The protruding amounts of the flange portions 13b and 13c are determined so that the side surfaces 21 and 22 (surfaces parallel to the optical axis L1) abut against the inner surface 23 of the intermediate member 15.

  The flange portion 13 b is a joint portion for joining the lens barrel 13 and the intermediate member 15, and a front surface 26 (surface on the subject side) of the flange portion 13 b is joined to the intermediate member 15. That is, the joint surface 41 of the lens barrel 13 and the intermediate member 15 is the front surface 26 of the flange portion 13b.

  Further, the flange portion 13b is forward of the center distance (hereinafter referred to as the length of the imaging lens 11) of 1/3 of the surface 11a closest to the subject side of the imaging lens 11 and the surface 11b closest to the imaging element 12 (subject side). ). More specifically, the length from the center of the surface 11a closest to the subject side of the imaging lens 11 to the joint surface 41 measured along the optical axis L1 is smaller than 1/3 of the length of the imaging lens 11. As described above, the position of the flange portion 13b is determined.

  The flange portion 13c is a projection provided to prevent the lens barrel 13 (the imaging lens 11) from being shaken. That is, when the lens barrel 13 holding the imaging lens 11 is fitted and joined to the intermediate member 15, the side surface 22 (surface parallel to the optical axis L1) of the flange portion 13c is in contact with the inner surface 23 of the intermediate member 15. By contacting, the central axis of the intermediate member 15 and the optical axis L1 are kept parallel.

The lens barrel 13 is made of, for example, a metal such as aluminum or brass, polycarbonate (PC), polyamide (PA), polyphthalamide (PPA), polyphenylene ether (PPE), polybutylene terephthalate (PBT), polyphenylene. It is formed of a resin typified by sulfide (PPS). When formed of metal, the lens barrel 13 preferably has a linear expansion coefficient of approximately 10 × 10 ⁻⁶ K ⁻¹ or more and 30 × 10 ⁻⁶ K ⁻¹ or less. When formed of resin, it is preferable that the linear expansion coefficient of the lens barrel 13 is approximately 10 × 10 ⁻⁶ K ⁻¹ or more and 70 × 10 ⁻⁶ K ⁻¹ or less. That is, if the linear expansion coefficient of the lens barrel 13 is set to 10 × 10 ⁻⁶ K ⁻¹ or more and 70 × 10 ⁻⁶ K ⁻¹ or less and the dimensions of the lens barrel 13 and the like are determined, an appropriate metal or resin can be used. Materials can be selected easily.

  The intermediate member 15 holds the lens barrel 13 at one end and is fixed to the lens holder 16 at the other end, so that the image pickup element 12 is positioned at the in-focus position of the image pickup lens 11. Then, the imaging lens 11 is fixed.

  The intermediate member 15 has a flange portion 15a that protrudes toward the inner peripheral surface side (optical axis L1 side) at the front end portion (end portion on the subject side). The rear surface 27 (the surface on the image sensor 12 side) of the flange portion 15a is in contact with and joined to the front surface 26 of the flange portion 13b of the lens barrel 13. The intermediate member 15 holds the lens barrel 13 by a joint surface (contact surface) 41 obtained by joining the rear surface 27 of the flange portion 15a and the front surface 26 of the flange portion 13b. The rear surface 27 of the flange portion 15a and the flange portion 13b are joined by an adhesive. The type of the adhesive is arbitrary, but it is preferable to use an adhesive that does not easily deteriorate due to a temperature change.

  A barrel portion 15b into which the lens barrel 13 is fitted is provided on the rear side (image pickup device 12 side) of the flange portion 15a. The diameter of the portion of the body portion 15b that fits with the flange portion 13b is determined so as to substantially match the diameter of the lens barrel 13 including the protruding amount of the flange portion 13b, and the inner surface 23 and the side surface of the flange portion 13b. 21 abuts. However, when the inner surface 23 of the body portion 15b and the side surface 21 of the flange portion 13b are not joined, when the intermediate member 15 or the lens barrel 13 is expanded (or contracted), the flange portion 13b is not deformed and the inner surface is not deformed. It slides with respect to the trunk portion 15 b while abutting against the body 23. In addition, when the flange part 13b is thin compared with the length from the front surface 26 of the flange part 13b to the lens surface 11b and there is little influence by expansion | swelling and shrinkage | contraction, the inner surface 23 and the side surface 21 may be joined.

  A fitting portion 15 c that fits the lens holder 16 is provided at the rear end portion of the intermediate member 15 (the end portion on the imaging element 12 side). The lens holder 16 includes a convex portion 16a that fits with the fitting portion 15c of the intermediate member 15, and a base portion 16b that the intermediate member 15 abuts against.

  When the fitting portion 15c is fitted to the lens holder 16, the inner surface 28 parallel to the optical axis L1 of the fitting portion 15c contacts the side surface 29 of the lens holder 16, and is perpendicular to the optical axis L1 of the fitting portion 15c. The inner surface 31 contacts the front surface 32 of the lens holder 16. However, since these are not joined, when the intermediate member 15 and the lens barrel 13 expand (shrink), the contact position slides relatively. When the length of the side surface 29 is shorter than that of the inner surface 23 of the intermediate member 15 and the influence of expansion and contraction is small, the inner surface 28 and the side surface 29 may be joined. The same applies to the inner surface 31 and the front surface 32.

  The end surface 35 of the fitting portion 15c is joined by an adhesive in a state where the end surface 35 is in contact with the front surface 33 of the base portion 16b. That is, the intermediate member 15 is fixed to the lens holder 16 by the joint surface 42 obtained by joining the end surface 35 of the fitting portion 15c and the front surface 33 of the base portion 16b.

  The rear surface 34 of the base portion 16 is bonded to the bonding position 43 of the drive substrate 17 by, for example, an adhesive. The drive substrate 17 is a substrate on which a circuit for driving the image sensor 12 is mounted. For example, the image sensor 12 is disposed at a substantially central position. At the center of the lens holder 16, the joint position 43 between the drive substrate 17 and the lens holder 16 is determined in advance so that the imaging device 12 is disposed. Therefore, the optical axis L <b> 1 coincides with the center of the image sensor 12 by fitting and joining the intermediate member 15 holding the lens barrel 13 to the lens holder 16.

The intermediate member 15 is formed of a resin typified by, for example, PC, PBT, PPS, liquid crystal polymer (LCP), and the like, and the linear expansion coefficient is approximately 0.1 × 10 ⁻⁶ K ⁻¹ or more and 40 × 10 ^−. It is preferably ⁶ K ⁻¹ or less. The material of the intermediate member 15 is selected so that at least the lens barrel 13 and the lens holder 16 have different linear expansion coefficients. That is, if the linear expansion coefficient of the intermediate member 15 is set to 0.1 × 10 ⁻⁶ K ⁻¹ or more and 40 × 10 ⁻⁶ K ⁻¹ or less and the dimensions and the like of the intermediate member 15 are determined, Therefore, an appropriate resin material can be easily selected.

  The lens holder 16 is made of, for example, a metal such as aluminum or brass, or a resin typified by PC, PA, PPA, PPE, PBT, or PPS. Therefore, when formed of metal, the linear expansion coefficient of the lens holder 16 is approximately 10 × 10.^-6K^-130 × 10 or more ^-6K^-1The following is preferable. When formed of resin, the coefficient of linear expansion of the lens holder 16 is approximately 10 × 10.^-6K^-170 × 10 or more^-6K^-1The following is preferable. That is, the linear expansion coefficient of the lens holder 16 is 10 × 10.^-6K^-170 × 10 or more^-6K^-1If the dimensions of the lens holder 16 and the like are determined below, an appropriate material can be easily selected from the above-described metal or resin. The material forming the lens holder 16 may be the same as that of the lens barrel 13.

  The imaging device 10 is covered with a cover member 19 in a state where the lens barrel 13 is attached to the lens holder 16 via the intermediate member 15, and is installed at a predetermined location (in a car interior) or the like. The cover member 19 exposes at least the imaging lens 11.

Hereinafter, the operation of the imaging device 10 will be described on the assumption that the intermediate member 15 and the lens holder 16 are bonded only at the bonding position 42. First, as shown in FIG. 3 (A), for example, in a normal temperature environment with an air temperature of 20 ° C., the back focus coincides with the imaging surface of the imaging element 12 from the rearmost surface 11b of the imaging lens 11, and the focal position of the subject image. Assume that they are assembled to fit. In this case, the back focus of the imaging lens 11 is A ₀ (mm), the length of the base portion 16b of the lens holder 16 is B ₀ (mm), and the lens holder 16 is connected to the lens holder 16 from the joint surface 41 of the lens barrel 13 and the intermediate member 15. The length of the joining surface 42 of the intermediate member 15 is C ₀ (mm), and the length D ₀ (mm) from the joining surface 41 to the position where the rearmost surface 11b of the imaging lens 11 intersects the optical axis. If the distance to the imaging surface of the imaging element 12 is Δ (mm), Δ = B ₀ + C ₀ −D ₀ −A ₀ .

  As shown in FIG. 3B, in a high temperature environment where the temperature around the imaging lens 10 is 80 ° C., for example, each part of the imaging device 10 expands, and the length of the base portion 16b of the lens holder 16 is B.₁(> B ₀), The length C from the joint surface 41 to the joint surface 42₁(> C₀), The length of the last surface 11b of the imaging lens 11 from the cemented surface 41 is D₁(> D₀) Each expands. When all the imaging lenses 11 are glass lenses, even if the expansion of each lens constituting the imaging lens 11 is ignored, the lens barrel 13 that directly holds the imaging lens 11 is expanded, so that the distance between the lenses is long. Therefore, the back focus is, for example, A₁Shortened to (mm) (A₁<A₀).

  Among these changes in length, expansion of the base portion 16b of the lens holder 16, expansion of the intermediate member 15 from the bonding surface 41 to the bonding surface 42, and shortening of the back focus due to expansion of the lens barrel 13 all increase the temperature. The operation of shifting the focus position to the subject side according to the above (so-called front pin) is shown. The expansion of the lens barrel 13 is an expansion that extends toward the image pickup device 12 with reference to the joint surface 41 of the intermediate member 15, and thus has an effect of canceling the expansion of the lens holder 16 and the intermediate member 15 and the shortening of the back focus. Therefore, the imaging device 10 has the lens barrel 13, the intermediate member 15, and the lens holder by fixing the distance between the imaging lens 11 and the imaging element 12 by the double structure of the lens barrel 13 and the intermediate member 15. By appropriately selecting each of the 16 materials (linear expansion coefficient) and the length between the joint surfaces 41, 42, and 43, it is possible to reduce at least the focus movement due to the temperature change. In particular, Δ = B₀+ C₀-D₀-A₀= B₁+ C ₁-D₁-A₁If the material (linear expansion coefficient) of the lens barrel 13, the intermediate member 15, and the lens holder 16 and the length between the joint surfaces 41, 42, and 43 are appropriately selected so as to satisfy Can be prevented.

  Note that depending on the configuration of the imaging lens 11 (particularly the length of the imaging lens 11), if the imaging lens 11 is simply held by the double structure of the lens barrel 13 and the intermediate member 15, an appropriate linear expansion coefficient is obtained. In some cases, the focus movement due to temperature change cannot be sufficiently reduced. Even in such a case, if the flange portion 13b is provided so that the cemented surface 41 is forward (subject side) of １ ／ of the length of the imaging lens 11, the length is almost independent of the length of the imaging lens 11. The lens barrel 13, the intermediate member 15, and the lens holder 16 can be selected from the above-mentioned materials, and the effect of reducing focus movement due to temperature changes can be easily obtained.

  If only the focus movement is to be reduced, the joint surface 41 protrudes forward from the surface 11a closest to the subject of the imaging lens 1.1, and the lens barrel 13 and the intermediate member 15 are joined in front of the imaging lens. May be.

  In addition to being able to reduce focus movement due to temperature changes as described above, the imaging apparatus 10 has a structure that prevents foreign matters such as liquids and dust from entering inside as described below.

  As shown in FIG. 4, in the imaging device 10, the side surface of the cylindrical portion 13 a of the lens barrel 13 and the side surface of the flange portion 15 a of the intermediate member 15 are substantially in contact with each other. There is a practical gap 51 enough to fit the barrel 13 into the intermediate member 15. Also, they are not bonded so that they can expand due to temperature changes. For this reason, when foreign matter such as liquid or dust adheres to the imaging device 10, foreign matter such as liquid or dust enters the inside of the imaging device 10 (the space between the lens barrel 13 and the intermediate member 15) through the gap 51. there's a possibility that. In particular, when the lens barrel 13 and the intermediate member 15 are repeatedly expanded and contracted in accordance with a temperature change, foreign matter such as liquid or dust attached to the front surface of the imaging device 10 may be drawn into the gap 51. However, in the case of the imaging device 10, the flange portion 13 b has a shape protruding so as to block the gap 51. , Acts as a dust barrier). For this reason, in the imaging device 10, even if foreign matter such as liquid or dust enters the gap 51, foreign matter such as liquid or dust is prevented from entering further into the interior (particularly in the space where the imaging device 12 is located). Can do. Even when the gap 51 is bonded, it is possible to prevent foreign matters such as liquid and dust from entering from the cracks or gaps generated in the bonded portion due to a change with time such as a temperature change.

  Further, when the lens barrel 13 and the intermediate member 15 are repeatedly expanded and contracted due to a temperature change, deterioration with time such as a crack or a gap may occur in the adhesive 53 on the bonding surface 41 in some cases. In the case of the imaging apparatus 10, since the joint surface 41 is on the surface 26 of the flange portion 13 b that acts as a levee, foreign matter such as liquid and dust is unlikely to enter from the time-degraded portion of the adhesive 53. .

  In addition, as shown in FIG. 5, it is preferable to provide the adhesive reservoir 61 in the base end part of the surface 26 of the flange part 13b. As described above, when the adhesive reservoir 61 is provided, the adhesive 53 can be prevented from protruding from the joint surface 41. When the adhesive 53 protrudes from the joint surface 41 to a portion other than the joint surface 41, the protruding portion of the adhesive 53 is damaged due to repeated expansion and contraction of the lens barrel 13 and the intermediate member 15 due to temperature change. In some cases, dust may be generated inside the image pickup apparatus 10. However, if the adhesive reservoir 61 is provided as described above so that the adhesive 53 does not protrude from the joint surface 41, such a problem is caused. It can be avoided.

  The adhesive reservoir 61 may be provided continuously around the entire circumference of the flange portion 13b like the adhesive reservoir 61a shown in FIG. 6, or a plurality of locations like the adhesive reservoir 61b shown in FIG. It may be divided into two.

  Further, as shown in FIG. 8, an adhesive reservoir 62 may be provided on the intermediate member 15 instead of the adhesive reservoir 61 of the flange portion 13b. The adhesive reservoir 62 may be provided over the entire circumference of the flange portion 15a of the intermediate member 15, or may be provided by being divided into a plurality of locations. The adhesive reservoir 61a of the flange portion 13b or the adhesive reservoir is provided. It is the same as 61b.

  In addition, after providing the adhesive reservoir 61a or the adhesive reservoir 61b in the flange part 13b, you may provide the adhesive reservoir 62 in the intermediate member 15 further. Further, instead of or together with the adhesive reservoirs 61a and 61b of the flange portion 13b and the adhesive reservoir 62 of the intermediate member 15, an adhesive reservoir may be provided on the side surface of the cylindrical portion 13a of the lens barrel 13.

  Further, the adhesive reservoirs 61a and 61b of the flange portion 13b are provided at the base end portion of the flange portion 13b. However, the adhesive reservoirs 61a and 61b may be positioned arbitrarily if the adhesive 53 does not protrude from the joint surface 41. It is. For example, the adhesive reservoirs 61a and 61b may be provided closer to the distal end than the proximal end portion of the flange portion 13b, such as the center of the flange portion 13b. The same applies when the adhesive reservoir 62 of the central member 15 is provided.

  5 to 8, the cross sections of the adhesive reservoirs 61 (61 a, 61 b) and 62 (the cross section including the surface including the optical axis L 1) are semicircular, but do not protrude from the joint surface 41. The cross-sectional shape of the adhesive reservoirs 61 (61a, 61b) and 62 is arbitrary as long as the excess adhesive 53 can be stored.

  In the imaging device 10, the intermediate member 15 and the lens holder 16 are bonded to each other at the end surface 35 of the fitting portion 15c and the front surface 33 of the base portion 16b. Instead of bonding them, as shown in FIG. A screw groove 67 is formed in the side surface 29 of the convex portion 16a of the lens holder 16 that is in contact with the imaging device 10 and the inner surface 28 of the fitting portion 15c of the intermediate member 15, and the intermediate member 15 and the lens holder 16 are screwed together. Also good.

  In the imaging apparatus 10, all the lenses constituting the imaging lens 11 are glass lenses, but plastic lenses may be used instead of glass lenses. A glass lens and a plastic lens may be used in combination. However, since a plastic lens has a larger thermal expansion coefficient than a glass lens, it is preferable to use a glass lens as much as possible in order to suppress focus movement due to temperature change.

  The imaging device 10 is suitable for a drive recorder for taking a driving record of a moving body such as an automobile or an in-vehicle camera for taking an image for assisting in driving or steering such as a garage. It is suitable for use in locations where the temperature change is large and foreign substances such as liquid and dust may adhere.

  In the imaging device 10, the side surface 21 of the flange portion 13 b is a flat surface, and the cross section of the flange portion 13 b by the surface including the optical axis L <b> 1 is a square, but the flange portion 13 b is a body portion of the lens barrel 13. As long as it protrudes from the side surface of 13a and can be joined to the intermediate member 15, any cross-sectional shape may be used. For example, the side surface 21 of the flange portion 13b may be formed in an arc shape to reduce the contact area between the side surface of the flange portion 13b and the inner surface 23 of the body portion 15b of the intermediate member 15. Thus, if the contact area between the side surface of the flange portion 13b and the intermediate member 15 is reduced, when the lens barrel 13 or the intermediate member 15 expands (shrinks) due to a temperature change, the flange portion 13b and the intermediate member 15 are in contact with each other. Since the friction is small, deformation of the flange portion 13b can be prevented even when the flange portion 13b is thin. Further, since the lens barrel 13 is evenly expanded (contracted) along the optical axis L1 without being caught by the intermediate member 15 on the side surface of the flange portion 13b, the optical axis L1 is unlikely to be shaken. The same applies to the flange portion 13c.

  In addition, the cross-sectional shape by the surface containing the optical axis L1 of the flange part 13b may be arbitrary shapes, if it can join with the flange part 15a of the intermediate member 15. FIG. For example, it may be a parallelogram or a trapezoid. The corner portion (the corner formed by the front surface 26 and the side surface 21) may be rounded or chamfered.

  In addition to the flange portion 13b for joining to the intermediate member 15, the imaging device 10 is provided with a flange portion 13c for preventing shaft shake. However, the flange portion 13c for preventing shaft shake is provided. Is not necessary.

DESCRIPTION OF SYMBOLS 10 Imaging device 11 Imaging lens 12 Image pick-up element 13 Lens barrel 13a Cylindrical part 13b, 13c Flange part 15 Intermediate member 16 Lens holder 17 Drive board 41, 42, 43 Joint surface

Claims (9)

An imaging lens that is held by a lens barrel and forms an image of a subject;
An image sensor that captures an image of the subject formed by the imaging lens;
The lens barrel is made of a material having a coefficient of linear expansion different from that of the lens barrel, and has a flange portion that comes into contact with the lens barrel on an inner peripheral surface at one end, and a subject side surface of the lens barrel and the imaging element of the flange portion An intermediate member for holding the lens barrel by bonding the side surface;
An imaging apparatus comprising:   The object side surface of the lens barrel and the contact surface of the flange portion are between the most object side surface and the most image sensor side surface of the imaging lens, and the imaging lens side of the imaging lens. The image pickup apparatus according to claim 1, wherein the image pickup apparatus is provided closer to the subject side than 間隔 of the distance between the surface closest to the subject and the surface closest to the imaging element.   The imaging apparatus according to claim 1, wherein the subject side surface of the lens barrel and the flange portion of the intermediate member are joined together by an adhesive.   At least one of the outer peripheral surface of the lens barrel and the inner peripheral surface of the intermediate member is provided with an adhesive reservoir adjacent to the subject-side surface of the lens barrel and the contact surface of the flange portion. The imaging device according to claim 1.   The imaging apparatus according to claim 4, wherein the adhesive reservoir is continuously provided on the entire outer periphery of the lens barrel or the inner periphery of the intermediate member.   The imaging apparatus according to claim 4, wherein the adhesive reservoir is provided at a part and a plurality of locations on the outer peripheral surface of the lens barrel or the inner peripheral surface of the intermediate member. The imaging device according to claim 1, wherein a linear expansion coefficient of the lens barrel is in a range of 10 × 10 ⁻⁶ K ⁻¹ or more and 70 × 10 ⁻⁶ K ⁻¹ or less. The imaging device according to claim 1, wherein a linear expansion coefficient of the intermediate member is in a range of 0.1 × 10 ⁻⁶ K ⁻¹ or more and 40 × 10 ⁻⁶ K ⁻¹ or less. The object side surface of the lens barrel to be joined to the flange portion of the intermediate member is a front surface of a flange portion provided to protrude outward from the outer peripheral surface of the lens barrel. The imaging apparatus of Claim 1.

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